General Relativity and Quantum Cosmology

Abstract: East and Pretorius (arXiv:1704.04791) have successfully evolved, using fully
non-linear numerical simulations, the superradiant instability of the Kerr
black hole (BH) triggered by a massive, complex vector field. Evolutions
terminate in stationary states of a vector field condensate synchronised with a
rotating BH horizon. We show these end points are fundamental states of Kerr
BHs with synchronised Proca hair. Motivated by the "experimental data" from
these simulations we suggest a universal (i.e. field-spin independent),
analytic model for the subset of BHs with sychronised hair that possess a
quasi-Kerr horizon, applicable in the weak hair regime. Comparing this model
with fully non-linear numerical solutions of BHs with synchronised scalar or
Proca hair, we show the model is accurate for hairy BHs that may emerge
dynamically from superradiance, whose domain we identify.

Comments:

5+2 pages, 7 figures; data files and Mathematica notebooks can be found in this URL: this http URL